A Deus, pela oportunidade oferecida, permitindo a realização de um sonho. Aos meus pais Darci e Acioní, que mesmo à distância, me apóiam e me encorajaram em todos os momentos. A minha amada namorada Larissa, pela felicidade a mim proporcionada, pela compreensão, carinho e companhia oferecida durante o tempo em que me mantive distante. Ao meu orientador Prof. Dr. Odemir Martinez Bruno, pela confiança depositada em mim, orientação e amizade. Aos amigos que fiz no convívio diário da universidade, em especial: Marco, André, Jarbas, João, Marcio e Cláudio. Ao Roberto e aos amigos do ciclismo, que me proporcionaram viagens, diversão e experiências únicas. Aos professores e funcionários do ICMC -USP e a todos que, direta ou indiretamente, colaboraram comigo. À FAPESP pelo apoio financeiro.i Palavras chaves: Visão Computacional, Análise de Textura, Taxonomia, Identificação Vegetal, Folha, Reconhecimento de Padrões.ii Abstract Biodiversity of species existing in the plant kingdom make the use of traditional models of taxonomy, a process of classification traditionally performed manually, a very complex and time-consuming task. Most of difficulties in that process result from the existence of few researches on plant classification using mathematical and computational methods. In this way, to contribute with the taxonomy techniques already developed, this study aims to develop and test a computational method for identifying plant species by leaf texture analysis. Motivated by the TreeVis project, this work is a comprehensive revision of texture analysis methods used in digital images (focus concentrated in features extraction and classification). This study investigates the applicability of traditional methods such as co-occurrence matrix, state of the art techniques as Gabor wavelets, and new and promising texture analysis methods, such as volumetric fractal dimension. In classification context is investigated methods of pattern recognition based on multivariate data analysis, artificial neural networks and committee machines. Although leaf classes present high similarity between classes and not appropriate similarity intraclasses, the results obtained are excellent. The best strategy for classification, using committee machines with descriptors of Gabor wavelets/color and volumetric fractal dimension/color, yielded a high probability of success, 96.32% in 40 classes studied. This result demonstrates how computational methods of images analysis, in particular texture analysis, can contribute and make more easier and faster the task of identifying plant species.